I've recently become interested in that whole period of time, and the region as well, and was curious. Despite being so close, I can't find anything about interactions (good or bad) between the two groups.

I know that there were wars in Finland, but they all seem to be later in time or mythological. (It doesn't help that "Finn" was historically used for both Sámi and Finnish people, which confuses things.) The earliest account I can find via my googling is the Battle at Hersdalr in 1008, and vague references to earlier potential campaigns.

If anybody knows about happenings in Finland proper before 1000 I would be insanely thankful. I'm really curious why, despite how close they are to each other, there's seems to be very little happening between Finland proper and Sweden, whether it be trading or warfare and I would really love to know more!

P.S. Adding this on late. Found a Wikipedia page dedicated to "Early Finnish wars" but it's kinda. Rough. The sources are either blocked by paywalls or in a language I don't understand lol. It answers a bit but I would like to know the opinions of historians!

Thank you all very much!!!